Cutting-off mechanism for bag making machines and the like



A. POTD EVIN Nov. 16, 1937.

CUTTING-OFF MECHANISM FOR BAGMAKING MACHINES AND THE LIKE Filed Nov. 7, 1935 ATTOR N EYS Patented Nov. 16, 1937 2,099,314

UNITED STATES PATENT "O'FFICE CUTTING-OFF MECHANISM non BAG MAK- me MACHINES AND THE LIKE Adolph Potdevin, Garden City, N. Y., assignor to Potdevin Machine Company, Brooklyn, N. Y., a corporation of New York Application November 7, 1935, Serial No. 48,614

3 Claims. (Cl. 164-68) This invention relates to improvements in bag with a gear 69 on the shaft 10 and with the making machines and is particularly directed to change gear 66. improved cutting ofl? mechanism oi the rotatable The discs 3| and 32, above referred to, are type, that is to say, wherein the cutters are over-specded with respect to the speed of the .mounted on rotatable rollers or cylinders, these forwarding rollers so t a the lineal p d Of 5 cylinders rotating at such a speed that the cylthese discs is higher than h Speed Of the P p inders make one complete revolution for each being advanc by the rw n r l This bag length severed from the bag tubing which is for the P p Of momentarily applying tenis fed continuously to the cutting ofl mechanism. 51011 to e p p t mp the severing Op My improved mechanism is designed primarily tion. This will be mentioned hereinafter. 10 to increase the range of the machine and to Each of e u i o y d s I5 and I6 facilitate the making'oi' bags of difierent l t is provided with a cutter 40 set into the face of In the accompanying drawing wher in I h the cylinder beside a land II, the cutting edge of illustrated one embodiment of my invention: h cutter projecting slightly b y the D Fig. 1 is an elevational view of the cutting of! rlphery of each cylinder as will be understood. is mechanism; These cutters cooperate with a cut oil plate 42 Fig. 2 is an nd i partly broken away of m over which the paper tubing, designated 50, is cutting cylinders; 1 drawn by the forwarding rollers 45, this cut oil? Fig. 3 i a plan vi of t mechanism bf plate and the cutters 40 providing a rolling pinch l; and cut for severing both walls of the tubing from one 20 Fig. 4 is a, view on th i H of PM 1 look. side to the other, whereby the tubing is divided ing in the direction of the arrows thereon. into bag lengths except that P the edge Referring to the drawing in detail, I designates of the tubing which extends ng the edges of the side frames of the machine to which a bracket the Plate This 15 mm tmfough by the 2 is adjustably secured by means of bolts 8. exerted on the paper by the verspeeded 2 The bracket 2 comprises two s 4 and rollers or discs 3| and 32 which, as above men- The arm 4 is provided with a pinion s and at its timed, are traveling at a higher Peripheral free end with a gear I meshing therewith. The Speed than the linear speed of the This arm 5 carries a gear 8 mounted on-a stub shaft apparatus is set out in the copendmg joint 64 and l meshing t pinion g application of myself and George Hampton, Se- 30 I5 d I6 designate pair of tt carrying rial No. 746,082, filed September 29, 1934. As inrollers mounted one above the other on shafts ca ed 0 the drawing. the p t 42 Which is I! and Hi. The shafts i1 and 88 are geared to moved forward automatically by the cutting'ofl each other by the gears l9 and 2., mechanism is retracted by a spring 43.

86 On one end of the shaft is is a disc 2| adjust- It will be evident from the description thus far 35 y s e to t She-ft I! y a bolt ".W given and from the drawing accompanying this permlts of the disc e rotated relatively application that the cut oil; cylinders l5 and I6 ga; fig f gg a g' gmake one revolution for each bag length. It is 40 a radial g 8 J g ig a g g: quite evident that with the cut off cylinders 0 pivotally fixed to the gear I as plainly seen in making one complete revolution for each bag Fig. length that the mere speeding up of the tubing would not suffice to vary the bag lengths sevi The gear 1 above referred to and which meshes with the pinion 6 is mounted on a shaft 29, which ered from the tubing by the cut off mechanism in the illustration is the drive shaft of the mabecause it is necessary in bag making-machinery 45 chine, this shaft extending. parallel to the shaft wherein mar! cutters are empmyed dividing l8 and carrying a cylinder 33 cooperating with the bag tubing int) bag lengths that the cutters discs 3| and 32 mounted on a shaft 65 above the when they engage the paper be traveling t subshaft 29, 1 stantially the same speed as the paper to avoid The drive shaft 29 is equipped at one side of tearing of t e paper. It becomes ecessary. .the machine with a change gear 86. o th shaft. therefore, to effect some adjustment of the cut- 10 of a pair of forwarding rollers 45 geared toting oif mechanism. One possibility would be to gether to run at the same speed by gears II, is vary the diameter oi! the cut of! cylinders. This 55 a swing bracket 81, carrying a pinion 8| meshing would necessitate removal of the cylinders I5 55 and I6 and substitution of cylinders of a different diameter.

Let us assume, for example, that in the present case it be desired to increase the bag length cut off by the cutters 40 as compared with the setting of the machine illustrated in the accompanying drawing. In this event thechange gear 66 will be removed and substituted by a change gear of larger diameter, thereby to increase the speed of rotation of the forwarding rollers 45 and With a corresponding increase in the speed of advance of the tubing 50, as will be understood. This change, however, does not alter the speed of rotation of the cut ofi cylinders l5 and i6 so that the knives 40 if allowed to contact with the paper for the cutting off operation would be traveling at a slower speed than the paper, which, as above pointed out, is undesirable. Accordingly it becomes necessary to alter the speed of rotation of the cut off cylinders l5 and I6 at the instant of cut-ofi so that'when the knives 40 contact the bag tubing they will be moving at approximately the same speed as the tubing.

To effect this adjustment it is merely necessary to loosen the bolts 29 and 22 by which the gear '1 and disc 2| are held to their respective shafts. The gear train comprising the gears 'l, 6 and 8, together with the disc 2|, are then rotated as a unit, with the cutters set about as indicated in Fig. 2, but of course with the cutters stationary. This shifting of the gear train just referred to will alter the setting of the disc 2| with respect to the cutters 40 so that the cutters 40, with the new setting, will be traveling at a different speed at the instant of cut-off than they were before. It will be appreciated of course that the disc 2| does not travel at uniform speed due to its crank connection to the gear 8. With this new setting, the operator then turns the machine over by hand, and if he finds the cutters 40 are not traveling at paper speed at the instant of cutoff he again makes an adjustment. As an alternative to this second adjustment he may alter the setting of the bracket 2 to shift the position of the block 24 in the slot 23 of the disc.

It will be seen from all of the foregoing that the present invention provides a construction in which While the cut-off cylinders make a complete revolution for each bag length, the speed of the cutters at the instant of cut-ofi is varied without varying the speed of the drive shaft of the machine, so that by varying the speed of the paper as it passes through the machine the length of the bag lengths will be varied, the cutters at each operation, however, traveling at paper speed.

It will be understood that changes may be made in the details of construction and arrangement of parts within the purview of my invention.

What I claim is:

1. In a machine for dividing tubing into bag lengths, the combination of forwarding rollers, a constant speed drive shaft therefor, a gear train intermediate said rollers and shaft, one gear thereof being removable and replaceable by another gear to vary the speed of said rollers, a pair of cut-off cylinders, cutters carried thereby, said cylinders making one revolution for each bag length, and means for driving said cylinders from said constant speed drive shaft and comprising a rotatable disc, a crank for driving said disc, whereby the cut-off cylinders between cutoffs are rotated at a surface speed different from their surface speed at the cut-off, and means for varying the setting of said disc circumferentially of the cut-off cylinders to accommodate the cut-off to variations in the speed of the forwarding rollers thereby to vary the bag lengths.

2. In a machine for severing tubing into bag lengths the combination of forwarding rollers for continuously advancing the tubing, a constant speed drive shaft therefor, a gear train intermediate said shaft and rollers, one gear thereof being removable and replaceable by another gear to vary the speed of said rollers, a pair of cutter-equipped cut-off cylinders and a cooperating plate for dividing the tubing into bag lengths with a rolling pinch cut, means for driving said cutter-equipped cylinders from said constant speed drive shaft, said means comprising a rotatable disc for driving said cut-off cylinders, a crank for driving the disc and means for varying the setting of said crank and disc to accommodate the cut-off cylinders to variations in the speed of the cut-ofi rollers thereby to produce a variation in the bag lengths.

3. In a machine of the class described, a pair of forwarding rollers for continuously advancing tubing which is to be divided into bag lengths, a constant speed drive shaft for said rollers, a gear train between said drive shaft and said rollers, a pair of cut-off cylinders for severing the tubing into bag lengths, said cylinders making one revolution for each bag length, adjustable means intermediate the said constant speed drive shaft and said cut-01f cylinders for transmitting power 

